Collection of yarns by over-end winding



June 24, 1969 A. c. JONES I 3,451,208

- a COLLECTION OF mans BY 'bvBR-END WINDING,

Filed July 11, 1967 Sheet of 2 A Horneys June 24, 1969 A. c. JONES 3, 0

COLLECTION OF YARNS BY bVER-END WINDING Filed July 11, 1967 Sheet 2 of 2 I nventor H4 fl/V C'a/V wm r/a/vis amJ-igwzmzm Attorney 3 United States Patent 3,451,208 COLLECTION OF YARNS BY OVER-END WINDING Alan Conway Jones, Pontypool, England, assignor to Imperial Chemical Industries Limited, London, England, a corporation of Great Britain Filed July 11, 1967, Ser. No. 652,483 Claims priority, application Great Britain, Aug. 4, 1966, 34,980/ 66 Int. Cl. B65h 54/04, 77/00; D0111 13/10 U.S. Cl. 57-156 6 Claims ABSTRACT OF THE DISCLOSURE Patterning in yarn packages wound with ring tilt by ringspindle apparatus is reduced by scrambling yarn delivery speed, and hence causing fluctuations in traveller velocity.

This invention relates to improvements in or relating to the collection of yarns by over-end winding, and to yarn packages so wound.

Background and field of the invention Various forms of over-end winding apparatus are known, for example those employing a ring and traveller yarn guide or the apparatus known as cap-spinning apparatus; but for convenience hereinafter in this specification reference will be made only to a ring and traveller device, although it will be appreciated that the present invention relates also to any other form of over-end winding apparatus.

There are occasions in the over-end winding of yarn packages, for instance double-taper comically-ended packages, when patterning occurs i.e. a fine surface relief pattern effect is obtained along the winding surface of the package.

This is due to the fact that the yarn is caused to be laid on to the package during at least part of the winding operation in the form of closely wound helical turns which may have a sinusoidal wave-form (or a triangular waveform) superimposed thereon, the maximum angle which the yarn makes to its mean angle of lay in each such waveform being at least 0.l.

When either a turn of yarn at a particular winding-on point includes a small integral number of such sinusoidal waves, or at a particular winding-on point a turn of yarn has a fraction of a sinusoidal wave which is a ratio of small integers, then the lay of the yarn at this winding-on point is evenly distributed over the surface of the package as it is being formed. However, immediately on either side of this point in the winding operation, when the relative disposition of the wave-form of adjacent turns either progresses or regresses, the parts of the waves having the maximum angle of inclination to the mean axis of the lay of the yarn on the packages merge together. In this case, the traversing action along the spindle axis of the ring rail supporting the ring and traveller yarn guide is no longer effective in separating the wave-form of the constituent turns of yarn and these will touch and form ridges, which are the basis of the patterning referred to above.

Such patterning may occur due to uncontrolable features associated with the winding operation, such as vibra tions of part of the winding apparatus, or some other aspect which will cause the yarn guide to oscillate in a vertical plane. Such displacement of the yarn guide can even be caused by ridges already formed on the package, simply by virtue of the yarn having finite dimensions; and thus, even under otherwise ideal winding conditions, there will be some tendency to generate patterning conditions. It will be appreciated that only very small forces are required See to cause the yarn to move uncontrollably in a plane parallel to the rotational axis of the spindle before being laid on to the package, as the major controlling force acting on the yarn is the winding-on tension, which at this point is at right angles to the rotational axis of the spindle.

On the other hand, such patterning may occur due to deliberately induced conditions of winding, such as when the axis of the ring of the ring-and-traveller yarn guide device is arranged to be inclined to the rotational axis of the package whereby a pronounced sinusoidal component is added to the lay of the turns of yarn on the package.

By deliberately tilting the axis of the ring of a ring and traveller device to a small angle of e.g. between 3 and 6 to the rotational axis of the package, it is possible to improve the stability of the spindle carrying the package, particularly if the yarn is a synthetic polymeric yarn with a relatively smooth surface, by providing that the turns of the yarn cross over each other in a desired manner, so that the turns of yarn are supported both in a radial and in an axial direction.

Such ring-tilt is also helpful in that the take-01f tension associated with the final layers of yarn to be unwound from the package is less than that associated with a package wound without deliberately induced ring tilt.

Deliberate tilting of the ring as a means of controlling the causes of package instability and unsatisfactory yarn properties is a means of increasing the weight of a conically-ended package, by using a greater taper angle for the conical end-portions than would otherwise be desirable and hence of increasing the economic use of the winding apparatus. 5 v a When patterning occurs, the layers of yarn are not securely laid in the regions of patterning, so that it will be understood that even if there is an overall improvement in package stability due to winding with ring-tilt, there may be patterning within the package, which will have the effect of causing package instability at certain points in the package.

In addition, although various forms of package build have been devised to reduce the effects of non-uniform retraction of the yarn on the package, due to various causes, at least so that prominent streaks are not present in the fabric into which the yarn is eventually made up, the beneficial attributes of such builds can be negative, if the yarn packing density on the container nevertheless is non-uniform due to patterning within the package.

Thus, if packages of yarn can be wound in which the yarn is laid on the package at substantially uniform tension throughout the winding operation, without the formation of patterning, and so that a stable package is produced defects in fabrics made of synthetic polymer yarns so wound, such as barr or warp-stripes, will be reduced in extent.

Patterning may also be a source of uncontrollable variations in the take-off tension of the yarn, due to turns of yarn becoming trapped; and, in any event, the package is unsightly.

Hence, to provide means whereby patterning is reduced in extent within a package comprises a main object of the present invention.

In addition it is an object of the present invention to reduce the extent of patterning in the package in a way which does not materially effect the yarn properties.

Summary of the invention It has now been found that fluctuations in the physical restraint imposed on the running yarn i.e. variations in the delivery of yarn to the package, can be arranged to be of such a magnitude that no adverse effect such as yarn breakages or looping accrue, or, unless these are desired for novelty purposes, no fabric streaks are produced, but

are such that there is a reduction of patterning within the package. Such a change in the winding conditions will be referred to hereinafter as a varying physical restraint of the defined form. A concomitant effect will be to cause the traveller speed, in a ring and traveller over-end winding system, to fluctuate.

According to one aspect of the present invention apparatus for producing a yarn package by over-end winding has means for causing the imposition of a varying physical restraint of the defined form on the running yarn.

It will be appreciated that a variation in the physical restraint of the defined form imposed on the running yarn may be caused by storing variable amounts of the yarn before it is delivered to the balloon, but after it has been delivered at a constant speed by the yarn processing part of the apparatus. Alternatively, the variation in physical restraint may be imposed on the yarn in the balloon, although this latter way may not be so convenient.

The yarn may engage a yarn-engaging member which is reciprocating in a plane at right angles to the general direction of movement of the yarn, and thus be displaced away from the path it would otherwise normally take, so that a variable amount of yarn is stored in this way.

In one form, the yarn-engaging member comprises a yarn guide which is arranged to be reciprocated by traverse mechanism known per se.

In another form, the yarn-engaging members comprises a rotating eccentric placed in the yarn path. Conveniently, the eccentric carries a pin around which the yarn is partially wrapped.

Generally, it is desirable that the yarn be delivered to the winding apparatus at a constant speed from a continuous supply, for example, freshly-spun yarn from a spinneret, or yarn from the drawing part of a drawtwist machine. Fluctuations in this speed are undesirable, as they may cause the yarn to break, or to form loops about the various components of the winding apparatus, and so subsequently to be broken; and for this reason, care is always taken to ensure that not even unintentional fluctuations in the delivery speed of the yarn to the winding apparatus shall occur. Nevertheless, it may be possible to devise processing apparatus of a complex form in order to be able to introduce fluctuations in the yarn delivery speed therefrom, and so to reduce patterning on the package according to the invention; and such more complex apparatus is to be considered to fall within the scope of the invention.

It will be appreciated that the imposition of the variable physical restraint of the defined form should normally be such that any concomitant variation in the yarn tension does not produce discernible streaks in fabric into which the yarn is eventually made-up, unless such streaks or other variable effects are desired, for novelty purposes.

According to another aspect of the present invention, a method of producing a yarn package by over-end winding, comprises causing the imposition on the running yarn of a varying physical restraint of the defined form continuously throughout the winding of the package.

Conveniently, the physical restraint on the running yarn is arranged to vary cyclically throughout the winding operation.

According to a further aspect, the present invention comprises a yarn package produced by the over-end winding apparatus referred to above, or to a yarn package when produced by the method of over-end winding referred to above.

The invention is of itself capable of reducing the patterning phenomenon for over-end wound yarn packages to a commercially useful degree, but it may sometimes be desirable to combine the imposition of variable physical restraint of the defined form (an essentially high frequency, or scrambling, technique) with other more radical variations in the winding conditions, such as longer term variations of the spindle speed.

Thus, the spindle speed may be gradually varied throughout the period of winding, for instance by being gradually reduced. Further, such spindle speed variation may have imposed on it abrupt shifts to values above or below the mean speed at the instants during the winding when regions of patterning are calculated to occur. Alternatively, the spindle speed may be shifted between two or more values during the full winding period, the instants of shifting again being programmed to occur at the calculated values of wind ratio likely to lead to patterning, so as to avoid such regions of patterning.

The invention may also be combined, if desired, with other scrambling techniques, such as the scrambling of the spindle speed, either alone or in combination with any of the above-mentioned programming techniques, and either at a given high frequency or at a plurality of given high frequencies or at a frequency dependent on the constant maintenance of a given ratio between it and the traverse or traveller frequency.

Brief description of the drawing One embodiment according to the present invention, and modifications thereof, will now be described by way of example, but not limitation, thereof, with reference to the accompanying drawing, in which:

FIGURE 1 is a diagrammatic representation of a modified drawtwist machine, and

FIGURE 2 illustrates in greater detail the device to cause the imposition of a varying physical restraint on the running yarn continuously throughout the formation of a package, comprising a rotating eccentric positioned in the yarn path between the draw rolls and the balloon guide of the draw twist machine.

The apparatus comprises a drawtwist machine for drawing a yarn made of synthetic polymer for example, a polyamide, and apparatus for collecting the drawn yarn in the form of a conically-ended package by means of overend winding.

The yarn Y is withdrawn from a cheese I mounted on a container 3 and passes through yarn guide means 5 to a pair of driven feed rolls 7. From these feed rolls the yarn is wrapped around an inclined snubbing pin 9 and is stretched to, say, five times its original length by passage around driven draw roll 11 with separator roll 13, which forward the yarn at a speed five times greater than that at which it is forwarded by the feed rolls.

After the draw rolls, the yarn passes through a balloon guide 15 to the winding apparatus, where it is wound in a package 17 on a cylindrical tube 19 rotatably mounted on a vertically-extending spindle 21. The yarn guide means, causing the yarn to be laid on the package, comprises a conventional ring 23 and traveller device 25 mounted on a ring rail 27, this ring rail being reciprocated along the spindle axis by a known form of builder mechanism 29, including a striker plate 31 secured to the ring rail for reciprocation therewith. At each end of each reciprocation stroke the plate is arranged to operate a mieroswitch (not shown) and so to cause the reversal of direction of movement of the ring rail. The positions of the microswitches are controlled respectively by two cams rotatably mounted on a shaft driven at a constant speed (not shown). A desirable package build is the so-called long-to-short build.

In order to improve the stability of the package, the axis of the ring of the ring and traveller yarn guide device is inclined at an angle of 3 to the axis of the spindle. Thus, the yarn is laid on the package in the form of closely-wound helical turns on which is superimposed a sinusoidal wave-form due to the inclination of the ring causing the traveller to have a small-amplitude oscillatory movement in the plane of the spindle axis, whereby the maximum angle which the yarn makes to its mean angle of lay in each such wave-form is at least 0.1.

In order to eliminate patterning that would otherwise be caused by such ring-tilt, or at least to reduce the extent to which it occurs, it is desirable to impose a varying physical restraint of the defined form on the running yarn throughout the winding operation, whereby the frequency of the sinusoidal wave-form is varied cyclically.

Suitable means for varying the physical restraint on the yarn comprises a rotating eccentric 33 positioned in the yarn path between the draw rolls and the balloon guide and arranged to cause the yarn path to be rapidly extended and contracted cyclically by a distance, say, of 4 inches during each of its revolutions. The eccentric comprises a rotatable arm 35, operably coupled to a drive shaft 37 driven by the drive means of the draw twist machine. At the extremity of the arm there is positioned a pin 39 around which the yarn is partially wrapped.

Care is nevertheless required to ensure that patterning on the package is reduced and not enhanced by the varying physical restraint of the defined form.

Thus, the eccentric is arranged to be rotated at a rate which is considerably faster than the traverse speed of the ring rail, but which is not a small multiple of the rate of rotation of the balloon, and is preferably less than one-eighth of that rate. In one winding process, the eccentric may therefore be arranged to rotate at a constant speed of 650 r.p.m.; but this value may be arranged to alter during the winding operation.

What I claim is:

1. A method of producing a yarn package by over-end winding, which method comprises travelling a yarn to an over-end wind-up means, and the improvement in which consists in causing the imposition of a varying physical restraint on the travelling yarn whereby the delivery speed of the yarn to the wind-up package is varied.

2. A method according to claim 1 in which the variation is cyclical and takes place throughout the winding of the package.

3. A method according to claim 2 in which the cycle time varies during the winding.

4. A method according to claim 2 in which the cycle time is less than the traverse time and greater than the time for a single rotation of the ballooning yarn but not a small multiple thereof.

'5. A method according to claim 1 in which the yarn is delivered at constant speed to means causing the imposition of varying physical restraint.

6. A method according to claim 1 in which the yarn is wound by a ring and traveller device, the axis of the ring of which is tilted at a small angle to the axis of rotation of the spindle.

References Cited UNITED STATES PATENTS 2,929,114 3/1960 Woods 5791 XR 2,948,931 8/ 1960 Smith. 3,137,987 6/1964 Potts 5755.5 3,148,416 9/1964 Hornbuckle 57-91 XR FOREIGN PATENTS 549,017 11/ 1942 Great Britain.

DONALD E. WATKINS, Primary Examiner.

US. Cl. X.R. 

